Aging is the single most important risk factor in human disease in developed countries, and it is thought that an understanding of aging mechanisms would prompt design of rational therapies against age-related diseases. A corollary is that a pharmacological agent that slows aging itself is likely to be effective against a wide spectrum of diseases. To discover what classes of chemical compounds slow aging, we will screen a large and diverse chemical library for extension in the lifespan of the nematode C. elegans. We have developed a number of automated screening methods that exploit C. elegans handling technology. We will also screen a library of compounds generally recognized as safe (GRAS) for extended lifespan to bias our search towards compounds that will prove useful in mammals. We will establish whether the compounds extend lifespan by acting on known pathways and determine their impact on general metabolism and stress resistance. We expect some compounds will prolong lifespan by novel mechanisms in which case we will identify the target proteins. Overall, we aim to identify a range of compounds that slow aging; these compounds will be leads for the development of therapeutics against a range of age-related diseases.